Security code enabled secure communication using RF technology

Hi Everyone?.
I have a project about secure communication between transmitter and receiver using RF modules enabled by security code. In my effort i try to identify components which are: Two micro controllers, RF modules(Transmitter and Receiver), RF encoder and Decoder, Antenna. So the problem to me is to know the selection of appropriate that components and to design a circuit diagram also coding micro controller to hide message.

Once you establish the requirement, it will drive your search for components. It always helps to have access to equipment and methods that are not widely available, but that is probably beyond the scope of your project.

I recommend you start by understanding PGP encryption. It is an open source starting point, that has features that should be good enough for your purposes. Only you can make that determination however.

Once you establish the processor and the development environment to be used, you can move on to frequency bands and modulation techniques. You need to do a much better job of defining your requirements.

Papabravo thanks, you give me a link for code, but i interested much on the circuit for that system of RF communication with micro
controller first. So if you have a link for circuit or any one with that circuit help me.

To hide message is no problem. But remember: a transmission pattern is also a message (without the direct meaning of its content.)
first of all you should detect the 'other' site and know the exact time to transmit one block and receive one (turnaround time) avoiding so the middle man.The middle man receive and evaluate date and transmit it at higher power. During receive they blank out the formal receiver with a directional antennae. Then turnaround is not correct.
Just receiving by 3 party is not to avoid. Sending a high speed burst encrypted and compressed with a not common modulation technique will reduce the time to detect.
This information is common and available at Internet look at Diffie-Hellman and modulation technique.
Now way to hide it for the government hence they have a huge tin of decryption specialist to open when needed.